A conventional bicycle rack 8 is shown in FIGS. 12A and 12B, and generally includes a connection device which is used to be connected with a sphere 70 fixed on a rear end of a vehicle which is not shown. The connection device includes a substantially C-shaped frame 82 including an open end and a slot 811 is defined in a bottom board 81 thereof. A U-shaped flange 812 extends from a top of the bottom bard 81 and encloses the slot 711. The sphere 70 is inserted from the open end and located within the slot 811 rested on the flange 812. A hole is defined through a top of the C-shaped frame 82 and a nut 821 is fixed to the top of the C-shaped frame 82, the hole communicates with the threaded hole in the nut 821. A threaded shank 83 threadedly extends through the nut 821 and the hole so as to press on the sphere 70.
However, the threaded shank 83 is easily loosened by the shaking during riding of the vehicle and once the threaded shank 83 does not well position the sphere 70, the bicycle rack could be separated from the sphere 70. Besides, the threaded shank 83 is exposed without any protection and any one can easily unscrew the threaded shank 83 to remove the bicycle rack together with the bicycles on the bicycle rack.
The present invention intends to provide a securing device which includes a knob threadedly connected to a bolt on a clamping unit which clamps the connection member/sphere of the vehicle, and a lock is used to connect the knob to the rack.
Besides, a quick release unit is used to allow the user to release the sphere from the securing device conveniently and quickly.